1. Field of the Invention
This invention relates to a cleaning liquid and a cleaning method for cleaning a magnetic head.
2. Description of the Related Art
The magnetic head loaded on a video tape recorder (VTR) tends to be scorched because magnetic powers dropped from the magnetic tape, dust and dirt from an external environment or the lubricant coated on a magnetic tape become affixed to the tape sliding surface of the magnetic head. The powdered foreign matter or scorched lubricant, if heaped, tend to affect the recording/reproducing characteristics of the magnetic head.
For cleaning the tape sliding surface of the magnetic head, a cleaning tape has so far been used.
This cleaning tape may be roughly classified into a wet type cleaning tape configured for coating the tape surface with a cleaning liquid, and a dry type cleaning tape configured for cleaning the tape surface by exploiting abrasion properties of the tape surface without using the cleaning liquid.
Of these, the wet type cleaning tape is widely used because it has a superior cleaning effect without affecting the head.
As the wet type cleaning tape, such a cleaning tape is known in which a cleaning liquid mainly composed of isopropyl alcohol is applied to a tape-shaped substrate having a cleaning layer formed on a film of vinyl-based resins. In addition, there is disclosed a wet type cleaning tape in Japanese Laying-Open publications 4-38712, 40349210 and 6-139531.
The cleaning liquids of the wet type cleaning tape, so far proposed, are, however, composed mainly of alcohol. The cleaning liquid, mainly composed of alcohol, while having a cleaning effect, consumes much time in drying, such that some time must elapse since cleaning until it becomes possible to use the VTR. Moreover, the cleaning liquid, left for prolonged time in an undried date, tends to be polluted in the interim. Also, since alcohol is inflammable, it must be handled with attention. In addition, it is likely to modify plastics or rubber.
Furthermore, the cleaning liquid, mainly composed of alcohol, tends to absorb water. If the moisture is present in the cleaning liquid, it is left after cleaning on the head, head cylinder or on the guide, thus causing sticking of the magnetic tape to the magnetic head. The moisture, thus left, also tends to oxidize the magnetic head, or allows dust and dirt to be again deposited on the magnetic head.
The cleaning liquid, capable of removing dust and dirt, is poor in the effect in preventing re-deposition thereof, such that the magnetic head or the guide tend to be contaminated in a short time after cleaning.
In the field of VTR, researches towards higher performance are proceeding, such that, in the case of a rotary head, for example, a large number of, such as ten or more, magnetic heads are loaded on a cylinder, and are run in rotation at a speed higher than 450 rpm. In such high performance structure, the cleaning is of critical importance because the pollution or moisture deposition on the head or the cylinder affect the VTR operation seriously. With this in view, it is mandatory to eliminate the above inconvenience and to develop a cleaning tape having a higher meritorious effect.